The invention relates to an optical radiator, especially for ultraviolet or infrared radiation, with a lamp bulb based cement-free at one end, out of which at least two connecting wires are brought, each through a pinch, one at the upper end and the other at the lower end of the lamp bulb, the first connecting wire being affixed at the upper end of the lamp bulb to the upper end of a stiff support bow, and the lower end of the stiff support bow being brought as a terminal pin through a first bore in a lamp base and is fastened to the latter with an anti-extraction lock.
The invention refers to an optical radiator, such as is used, for example, as a heat radiator or as an UV radiator for tanning, sterilization, surface treatment, or for drying and curing thin coatings. Due to the high power of UV or IR radiators, relatively high temperatures are produced, so that thermal expansion and heat stress which they entail are important in the structural configuration and choice of materials of the radiators.
Such radiators are disclosed in German Patent Application 197 52 120 A1, which discloses an optical radiator based cement-free at one end in a ceramic lamp base, through which two terminal pins are brought for connecting the connecting wires protruding at top and bottom from the lamp bulb. The terminal pin for connecting the upper connecting wire is made in one piece as a stiff support bow. The terminal pin for connecting the lower connecting wire either is bent or it comes out straight. If this terminal pin is straight, the lower connecting wire is bent. The connection between terminal pins or the stiff support bow and the connecting wires respectively is performed preferentially by spot welding. The two terminal pins are provided with an anti-extraction lock each at the upper and the lower ends of the bores in the lamp base. The term, anti-extraction lock is to be understood to mean an appropriate configuration of the terminal pin or a component clutching the terminal pin, whereby the complete extraction of the terminal pin through the bore in the lamp base is prevented. This does not prevent free play of the terminal pin within the bore.
The invention is addressed to the problem of offering an optical radiator which can be made quickly and inexpensively from a minimum of parts.
The problem is solved in that the second connecting wire at the lower end of the lamp bulb is brought loosely through a second bore in the lamp base. Thus, on the one hand there is no need for an additional terminal pin for connecting this second connecting wire to the lower end of the lamp bulb, nor on the other hand for anti-extraction locks on this terminal pin. The second connecting wire at the lower end of the lamp bulb is accordingly not connected to the lamp base, and the second bore serves only to guide the second connecting wire. By the floating suspension of the lamp bulb at one end, thermal expansion due to the high power and temperatures of the UV or IR radiators are easily possible. The mounting of the radiator is substantially simplified, which in addition to the saving of parts has a cost reducing effect.
It is especially advantageous if the second connecting wire and the lower end of the stiff support bow, used as terminal pin, are connected each on the side of the lamp base remote from the lamp base with a flexible conductor. The connection can be made by welding, for example. To prevent short circuits, the conductors should be surrounded, for example, by an insulating fabric layer. Ideally, the lamp base has a mounting device. The term, mounting device, is to be understood as any conceivable structural configuration of the lamp base that is suitable for fastening the optical radiator to a later place of use. Screw threading, plugs or clamp connections can be used. The mounting device therefore serves merely for mechanical fixation, not for the electrical connection of the radiator. The electrical connection of the radiator is performed through flexible conductors so that relief of the electrical wiring from tensional stresses is achieved by the mounting device.
One possible embodiment of the mounting device is formed by two openings or notches on the side of the lamp base remote from the lamp bulb. Screws, for example, can be passed through the two openings in order to affix the radiator to the place of use. The two openings can, however, also be used for a plug-in connection.
It is especially advantageous if the stiff support bow has a bulge in the area of the lamp base which acts simultaneously as an anti-extraction and rotation lock. Appropriate for the purpose are U-shaped bends of the stiff support bow or bulges which are formed by a change in the cross section of the stiff support bow.
The length of the optical radiator can advantageously be shortened if the lamp base on the side facing the lamp bulb has a recess in the area of the second bore, and if the pinch on the lower end of the lamp bulb through which the second connecting wire is brought out, enters at least possible into the recess. This embodiment is to be recommended especially if there is little space available for the installation of the radiator at the place of use.
It is advantageous also if the first bore on the side of the lamp base facing the lamp bulb is adapted in shape to serve to prevent rotation of the bulge in the stiff support bow.
FIGS. 1 to 6d show by way of example a possible embodiment of an optical radiator according to the invention, wherein concealed lines are drawn thinner than visible lines.